The present disclosure relates to cover systems for open-topped containers, such as dump bodies, refuse haulers, grain trailers and the like, and particularly to drive systems for conveying the cover across the container. These cover systems utilize flexible covers, such as tarpaulins, that are pulled across the open top of the container body. The flexible cover is wound onto a roller as the cover is moved to its open or stowed position and unwound from the roller as the cover is moved to a closed position covering the container body. An arm assembly supports the opposite ends of the flexible to control the movement of the cover to and from its end positions.
An exemplary side-to-side system is depicted in FIG. 1a. The vehicle V includes a tractor T and a trailer body B, which may be a dump body, grain hauler and the like. A tarping system 10 is mounted to the trailer with a cover or tarpaulin 11 sized to extend the entire length of the open top O of the trailer body, and to span the width of the open top when the tarping system is in its closed configuration. A drive mechanism 12 is engaged to a roller supporting the cover 11 that is configured to move the cover from one side of the trailer body B to the other. A support mechanism 13 is engaged to the opposite end of the cover roller to support the cover as it is deployed or retracted. In a typical side-to-side cover system, the drive mechanism 12 rotates the roller and cover so that the cover travels over the end caps C of the trailer body.
A typical front-to-back cover system is shown in FIG. 1b. The cover system 10′ is mounted on a vehicle V, which may be a dump truck with a dump body B over which the tarpaulin 11′ extends. The cover system 11′ includes a bail arm assembly 12′ that is connected to one end of the tarpaulin 11′ and that may be biased by a spring mechanism 13′ toward the covering position shown in FIG. 1b. The tarpaulin is wound onto a roller assembly 14′ at one end of the body B′. A drive mechanism 15′ mounted to the side of the roller assembly rotates the roller assembly to retract the tarpaulin 11′ against the biasing force of the spring mechanism 13′. The drive mechanism 15′ includes a motor with its output shaft directly driving the roller assembly 14′.
The design of cover or tarping systems is subject to certain government regulations. One government regulation is that the cover system cannot extend more than three inches beyond the side of the trailer. Another requirement in the art is that the envelop of the cover system be as small as possible in the space between the truck and the trailer. As illustrated by the side-to-side system in FIG. 2a and particularly the front-to-back system in FIG. 3a, prior art mechanisms M for driving the cover system typically project outward from the side of the trailer body B by a dimension Emax that exceeds the three inch regulation. The prior art mechanisms M in the side-to-side systems of FIG. 2a also typically project a depth Dmax from the forward end of the trailer body B. This depth Dmax is typically seven to fourteen inches which is a significant incursion into the desired space for a headache rack or a cab-mounted storage rack. There is a continuing need for a cover system, whether a side-to-side or a front-to-back system, that is capable of generating the torque profile needed to move a container cover, while still maintaining a package dimension that meets all government width regulations and minimizes the envelop at the front of the trailer.